Vibration at High Speed 2004 Q45

[Romfrock]

Help, please. I love my 2004 Q45 (standard suspension). About 2 years ago I replaced the ugly OE wheels with after-market by Montegi. Last summer I replaced the OE tires at Kaufman Tire/Atlanta. Since then I've had a mild but annoying vibration when going >65MPH. It gets worse at 70-75MPH. I've been back to Kaufman at least 10 times. Tires have been replaced twice. The've checked the wheels -- told me they are perfectly round. I'm satisfied they've done everything they can do to the tire/wheel assembly. Is there a likely cause for vibration? What kind of specialist would you go to for a complete diagnostic without getting raped? (I can't walk into my Inifity dealer here without spending at least $500 it seems) Appreciate any guidance. Thanks.

[MaximA32]

Get them road force balanced. Should be problem solved.